Teeth that have LOST a pit-and-fissure sealant show which caries susceptibility?

Correct answer: A. Lower susceptibility than teeth that were never sealed

• A. CORRECT. This is a consistent and reassuring finding of the sealant literature: teeth that have lost their sealant remain at LOWER caries risk than teeth never sealed at all. Two mechanisms explain it. First, resin TAGS remain mechanically locked into the etched enamel of the deepest fissure even after the bulk of the sealant has worn away, continuing to obstruct the most caries-susceptible site. Second, the tooth was protected during the years of HIGHEST susceptibility — the immediate post-eruptive period before enamel maturation is complete.
• B. There is no evidence that sealant loss increases risk above baseline. This is the concern that used to be raised about 'sealing in' caries, which has been laid to rest: bacteria sealed beneath an intact sealant become non-viable as their nutrient supply is cut off.
• C. A fully retained sealant is obviously more protective than a lost one; that is why sealants must be checked at every recall and repaired or replaced when partially lost.
• D. Equivalence to never-sealed teeth would mean the sealant conferred no lasting benefit, which the retention studies contradict.

Note: Practical corollary: sealant retention should be assessed at every recall visit and deficient sealants repaired — a repaired sealant performs as well as an original. This is also why sealant placement remains cost-effective even with imperfect retention rates.